:root {
    --bg: #fafafa;
    --bg-alt: #f2f2f2;
    --bg-card: #ffffff;
    --text: #1a1a1a;
    --text-muted: #6b6b6b;
    --text-light: #999;
    --accent: #e53e3e;
    --accent-hover: #c53030;
    --green: #38a169;
    --green-hover: #2f855a;
    --border: #e8e8e8;
    --border-light: #f0f0f0;
    --radius: 8px;
    --radius-lg: 12px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --font-body: 'DM Sans', -apple-system, sans-serif;
    --font-mono: 'Space Mono', monospace;
    --max-width: 1280px;
    --checker: repeating-conic-gradient(#e0e0e0 0% 25%, transparent 0% 50%) 0 0 / 16px 16px;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-body); color: var(--text); background: var(--bg); line-height: 1.6; -webkit-font-smoothing: antialiased; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* NAV */
.nav { position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,0.92); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border-light); }
.nav__inner { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; height: 60px; }
.nav__logo { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); }
.nav__logo-icon { background: var(--text); color: #fff; font-family: var(--font-mono); font-size: 11px; font-weight: 700; padding: 4px 6px; border-radius: 6px; letter-spacing: -0.5px; }
.nav__logo-text { font-weight: 700; font-size: 17px; letter-spacing: -0.3px; }
.nav__links { display: flex; align-items: center; gap: 24px; }
.nav__link { text-decoration: none; color: var(--text-muted); font-size: 14px; font-weight: 500; transition: color 0.2s; }
.nav__link:hover { color: var(--text); }
.nav__menu-btn { display: none; background: none; border: none; cursor: pointer; color: var(--text); }
@media (max-width: 768px) {
    .nav__menu-btn { display: block; }
    .nav__links { display: none; position: absolute; top: 60px; left: 0; right: 0; background: #fff; flex-direction: column; padding: 16px 24px; border-bottom: 1px solid var(--border); gap: 12px; }
    .nav__links--open { display: flex; }
}

/* HERO */
.hero { text-align: center; padding: 80px 24px 48px; }
.hero__title { font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 700; line-height: 1.1; letter-spacing: -1.5px; margin-bottom: 16px; }
.hero__sub { color: var(--text-muted); font-size: 17px; max-width: 520px; margin: 0 auto; line-height: 1.5; }

/* TAGS */
.tags { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; padding: 24px; }
.tag { padding: 6px 16px; border: 1px solid var(--border); border-radius: 100px; font-size: 13px; color: var(--text-muted); text-decoration: none; transition: all 0.2s; cursor: pointer; background: transparent; font-family: var(--font-body); }
.tag:hover, .tag.active { background: var(--text); color: #fff; border-color: var(--text); }

/* SECTION */
.section { padding: 48px 0; }
.section-title { font-size: 24px; font-weight: 700; letter-spacing: -0.5px; margin-bottom: 8px; }
.section-sub { color: var(--text-muted); font-size: 15px; margin-bottom: 32px; }
.section-label { display: inline-block; background: var(--accent); color: #fff; font-size: 11px; font-weight: 700; padding: 3px 10px; border-radius: 4px; letter-spacing: 0.5px; text-transform: uppercase; margin-bottom: 12px; }

/* TOOLS GRID */
.tools-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; }

/* TOOL CARD */
.tool-card { display: flex; flex-direction: column; padding: 24px; background: var(--bg-card); border: 1px solid var(--border-light); border-radius: var(--radius-lg); text-decoration: none; color: var(--text); transition: all 0.25s ease; }
.tool-card:hover { border-color: var(--border); box-shadow: var(--shadow-md); transform: translateY(-2px); }
.tool-card__icon { font-size: 28px; margin-bottom: 12px; opacity: 0.8; }
.tool-card__name { font-size: 15px; font-weight: 600; margin-bottom: 4px; }
.tool-card__desc { font-size: 13px; color: var(--text-muted); line-height: 1.4; }

/* TOOL PAGE HERO */
.tool-hero { text-align: center; padding: 60px 24px 32px; }
.tool-hero__title { font-size: clamp(1.75rem, 4vw, 2.5rem); font-weight: 700; letter-spacing: -1px; margin-bottom: 12px; }
.tool-hero__desc { color: var(--text-muted); font-size: 16px; max-width: 560px; margin: 0 auto; }

/* UPLOAD */
.upload-area { max-width: 900px; margin: 0 auto; padding: 0 24px; }
.upload-zone { border: 2px dashed var(--border); border-radius: var(--radius-lg); padding: 48px; text-align: center; cursor: pointer; transition: all 0.2s; background: var(--bg-card); position: relative; }
.upload-zone:hover, .upload-zone.dragover { border-color: var(--text); background: var(--bg-alt); }
.upload-zone__icon { font-size: 36px; margin-bottom: 12px; opacity: 0.4; }
.upload-zone__text { font-size: 15px; font-weight: 600; margin-bottom: 4px; }
.upload-zone__hint { font-size: 13px; color: var(--text-light); }
.upload-zone input[type="file"] { position: absolute; inset: 0; opacity: 0; cursor: pointer; }

/* BULK */
.bulk-thumbs { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.bulk-thumb { width: 64px; height: 64px; border-radius: 6px; object-fit: cover; border: 2px solid var(--border-light); cursor: pointer; }
.bulk-thumb.active { border-color: var(--accent); }
.bulk-count { font-size: 13px; color: var(--text-muted); margin-top: 8px; }

/* CONTROLS */
.controls { max-width: 900px; margin: 24px auto; padding: 0 24px; }
.controls__panel { background: var(--bg-card); border: 1px solid var(--border-light); border-radius: var(--radius-lg); padding: 24px; }
.control-group { margin-bottom: 20px; }
.control-group:last-child { margin-bottom: 0; }
.control-label { display: flex; justify-content: space-between; align-items: center; font-size: 13px; font-weight: 600; margin-bottom: 8px; }
.control-value { font-family: var(--font-mono); font-size: 12px; color: var(--text-muted); background: var(--bg-alt); padding: 2px 8px; border-radius: 4px; }

/* RANGE */
input[type="range"] { -webkit-appearance: none; appearance: none; width: 100%; height: 6px; background: var(--bg-alt); border-radius: 3px; outline: none; }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 20px; height: 20px; background: var(--text); border-radius: 50%; cursor: pointer; transition: transform 0.15s; }
input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.2); }
input[type="range"]::-moz-range-thumb { width: 20px; height: 20px; background: var(--text); border-radius: 50%; border: none; cursor: pointer; }

/* PREVIEW */
.preview { max-width: 900px; margin: 24px auto; padding: 0 24px; }
.preview__grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 640px) { .preview__grid { grid-template-columns: 1fr; } }
.preview__panel { border-radius: var(--radius-lg); overflow: hidden; position: relative; background: var(--checker); }
.preview__label { position: absolute; top: 12px; left: 12px; font-size: 11px; font-weight: 700; letter-spacing: 0.5px; text-transform: uppercase; padding: 4px 10px; border-radius: 4px; z-index: 2; }
.preview__label--original { background: var(--text); color: #fff; }
.preview__label--result { color: var(--accent); border: 1px solid var(--accent); background: rgba(255,255,255,0.9); }
.preview__img { width: 100%; display: block; min-height: 200px; object-fit: contain; background: var(--checker); }
.preview__placeholder { display: flex; align-items: center; justify-content: center; min-height: 300px; color: var(--text-light); font-size: 14px; }

/* BUTTONS */
.btn-row { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin: 24px 0; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 28px; font-size: 14px; font-weight: 600; font-family: var(--font-body); border-radius: var(--radius); cursor: pointer; transition: all 0.2s; border: none; text-decoration: none; }
.btn--primary { background: var(--accent); color: #fff; }
.btn--primary:hover { background: var(--accent-hover); }
.btn--success { background: var(--green); color: #fff; }
.btn--success:hover { background: var(--green-hover); }
.btn--outline { background: transparent; border: 1px solid var(--border); color: var(--text); }
.btn--outline:hover { border-color: var(--text); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }

/* SEO CONTENT */
.seo-content { max-width: 700px; margin: 48px auto; padding: 0 24px; }
.seo-content h2 { font-size: 22px; font-weight: 700; letter-spacing: -0.5px; margin-bottom: 12px; margin-top: 32px; }
.seo-content h2:first-child { margin-top: 0; }
.seo-content p { color: var(--text-muted); font-size: 15px; line-height: 1.7; margin-bottom: 16px; }
.seo-content ul { color: var(--text-muted); font-size: 15px; line-height: 1.7; margin-bottom: 16px; padding-left: 24px; }

/* FAQ */
.faq { max-width: 700px; margin: 0 auto 48px; padding: 0 24px; }
.faq__title { font-size: 22px; font-weight: 700; margin-bottom: 20px; letter-spacing: -0.5px; }
.faq__item { border-bottom: 1px solid var(--border-light); padding: 16px 0; }
.faq__q { font-weight: 600; font-size: 15px; margin-bottom: 6px; }
.faq__a { color: var(--text-muted); font-size: 14px; line-height: 1.6; }

/* RELATED TOOLS */
.related-tools { padding: 48px 0; background: var(--bg-alt); }
.related-tools .section-title { margin-bottom: 24px; }

/* FOOTER */
.footer { border-top: 1px solid var(--border-light); padding: 48px 0 24px; }
.footer__inner { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
.footer__grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
@media (max-width: 768px) { .footer__grid { grid-template-columns: 1fr 1fr; gap: 24px; } }
@media (max-width: 480px) { .footer__grid { grid-template-columns: 1fr; } }
.footer__desc { color: var(--text-muted); font-size: 13px; margin-top: 12px; line-height: 1.5; }
.footer__heading { font-size: 13px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; margin-bottom: 12px; }
.footer__link { display: block; text-decoration: none; color: var(--text-muted); font-size: 13px; padding: 3px 0; transition: color 0.2s; }
.footer__link:hover { color: var(--text); }
.footer__bottom { border-top: 1px solid var(--border-light); padding-top: 20px; font-size: 12px; color: var(--text-light); }

/* CALC */
.calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; max-width: 700px; margin: 0 auto; }
@media (max-width: 640px) { .calc-grid { grid-template-columns: 1fr; } }
.calc-panel { background: var(--bg-card); border: 1px solid var(--border-light); border-radius: var(--radius-lg); padding: 24px; }
.calc-panel__title { font-size: 14px; font-weight: 700; margin-bottom: 16px; }
.input-group { margin-bottom: 12px; }
.input-group label { display: block; font-size: 12px; font-weight: 600; color: var(--text-muted); margin-bottom: 4px; }
.input-group input[type="number"], .input-group select { width: 100%; padding: 10px 12px; border: 1px solid var(--border); border-radius: var(--radius); font-size: 14px; font-family: var(--font-mono); background: var(--bg); color: var(--text); outline: none; transition: border-color 0.2s; }
.input-group input:focus, .input-group select:focus { border-color: var(--text); }
.ratio-display { text-align: center; padding: 20px; background: var(--bg-alt); border-radius: var(--radius); margin-top: 16px; }
.ratio-display__value { font-family: var(--font-mono); font-size: 28px; font-weight: 700; }
.ratio-display__label { font-size: 12px; color: var(--text-muted); margin-top: 4px; }

/* PALETTE */
.palette-grid { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 16px; }
.palette-swatch { width: 80px; height: 80px; border-radius: var(--radius); cursor: pointer; position: relative; transition: transform 0.2s; border: 2px solid var(--border-light); }
.palette-swatch:hover { transform: scale(1.05); }
.palette-swatch__hex { position: absolute; bottom: 0; left: 0; right: 0; background: rgba(0,0,0,0.6); color: #fff; font-family: var(--font-mono); font-size: 10px; text-align: center; padding: 3px; border-radius: 0 0 6px 6px; }

/* ANIM */
@keyframes fadeUp { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: translateY(0); } }
.fade-up { animation: fadeUp 0.5s ease-out forwards; }